1. Field of the Invention
The present invention pertains to a mounting frame or curb for at least two packaged air conditioning units and which includes combined return air and supply air plenums for conducting air through one or both of the air conditioning units which are connected to common building return and supply air ducts through the curb.
2. Background
The development of packaged air conditioning units for commercial building applications has been well accepted, particularly, in regard to units which are adapted for mounting on building rooftops and other horizontal surfaces. So-called packaged air conditioning units typically include circulating fans, air cooling and heating heat exchangers or elements, and filters, all mounted within a cabinet or enclosure and usually having air inlet and discharge openings formed in the bottom wall thereof. These packaged units are typically mounted on a subframe supported by the building roof or other structure and common return and supply air ducting for the building air circulating system is connected to the return air and supply air openings in the enclosures.
However, the demand for ever increasing capacity of packaged commercial air conditioning systems and the desire for reliability in such systems has made it desirable to consider systems of multiple air conditioning units mounted in a generally clustered arrangement to facilitate the design of air ducting, power supply and control wiring and other requirements of the systems. In this regard the desire for clustered arrangements of multiple air conditioning units has resulted in the development of the present invention which solves the problem of providing a suitable mounting structure for multiple side-by-side units while at the same time providing return air and supply air ducting for conducting the recirculating conditioned air from the building, through the air conditioning units and back into the building air circulation system.